This research was initiated in 1996 when we discovered that the common fungi, Aureobasidium pullulans and Rhodotorula glutinis, which commonly live on apple surfaces, are able to cause russet. We currently feel that these microbial causes of russet are important on several apple cultivars. Our goals have been to study the biology of these fungi, determine under what conditions they cause russet and identify commercially and environmentally sound methods for control.